The present invention relates to emergency alert systems and more particularly to emergency alert and building occupant evacuation control systems.
The problem of alerting building occupants as to the existence of an emergency condition, such as a fire, explosion or the like and effecting a quick and orderly evacuation of the building occupants has been a long standing one. For example, many building occupants learn of the existence of a fire and/or smoke condition on the premises only when they hear a fire alarm bell or actually see or smell smoke or are advised thereof by word of mouth. When so advised, they normally try to seek out the closest fire exit door and try to leave the affected area or building through such exits. Unfortunately, the delay in learning of the emergency condition can seriously jeopardize their prospects for safe evacuation of the building premises.
Virtually all buildings are provided with signs indicating the location of door exits to be used by the building occupants in the event of fire or other emergency requiring prompt evacuation of the building premises. Such exit signs usually take the form of a flat rectangular sign bearing the word EXIT, or an illuminated box-like sign with EXIT on the front face thereof. Such signs are usually affixed to the building wall directly above the doorway intended to serve as the emergency exit.
The occurrence of a fire in the building is generally accompanied by smoke rapidly flling the affected areas which makes it very difficult, if not impossible, for the room occupants to see such conventional exit signs even if they are illuminated by ordinary lighting means such as by an incandescent light bulbs, particularly since such signs are usually located near the ceiling where the smoke is densest. Furthermore, it has been found that because they cannot see about them, the occupants of such a smoke filled room tend to lose their sense of orientation or direction and thus unable, by their own efforts, to find the fire exits, even if they remember their location. In addition, the emotional stress and sense of shock, excitement and possibly panic which generally afflicts persons suddenly finding themselves subject to a dire emergency such as a fire, further inhibits their ability to navigate their way to the fire exits, particularly where they must navigate through winding corridors to reach the fire exits.
It should be further noted that in many instances it is undesirable and even very dangerous for the building occupants to choose a particular fire exit as an escape route since such route may lead them into the path of the fire and smoke or other danger such as collapse of portions of the building structure. Thus, if a building floor has first and second fire exits at opposite sides of the floor leading respectively to their adjacent stairwells and if the fire danger is more severe in the area adjacent the fire exit, it is obviously essential that the occupants avoid the first fire exit at all and use the second fire exit. Clearly, in times of emotional stress and loss of directional orientation and visibility which are characteristic of emergency situations such as fires the occupants cannot be relied upon to make the proper decisions as to choice of appropriate fire exit. Thus, it has been found that in such cases the occupants often choose a particular exit door merely because others before them have chosen that exit, thus creating a stampede situation.
The foregoing emergency signalling and evacuation problems are greatly aggravated in the case of high-rise buildngs, both commercial and residential, particularly office buildings which may have tens of thousands of occupants and where quick, safe and orderly evacuation of the building premises is virtually impossible by conventional means.
It is therefore an object of the present invention to provide hazardous condition detection, signalling and evacuation control system which is operative to safely evacuate the occupants from a given area in the event of such hazardous condition.
It is a further object of the present invention to provide a fire signalling and evacuation control system of the character described which is operative to detect the occurrence of a fire and/or smoke in a room or building, to alert the building occupants thereof and to direct the evacuation of the occupants through the appropriate exit routes.